'Easy' does not seem to tally with the time it is taking people to do this one. Where do 'mild and 'tricky' come in the pecking order? We don't get given these options. Assume it is easy, mild, moderate, tricky, hard. Very easy to make a mistake with no means of finding where one went wrong except by use of 'show wrong' which always gives me a sense of failure! Also, difficult to disentangle all the possible digits in any one square even whilst obeying all the rules.

Posted 13th Aug 2012 at 23:51

gareth Administrator Daily subscriber Has not played this puzzle yet

Easy < Mild < Moderate < Tricky < Hard < Fiendish

Users can choose easy, moderate or hard and the others are based on equal division of the ratings count into sixths once it is averaged. In fact it's clear I should bias this to make the easy band narrower and the hard band wider.

Until several months ago puzzles were rated on a scale of 1 to 10, but 99% of users never selected anything other than 1, 2 or 3 when rating a puzzle - or occasionally 10. The 4, 5, 6, 7, 8, 9 were not used, essentially. So I simplified it to easy, moderate, hard.

Other sites such as Youtube have switched to an even simpler "good" or "bad" (thumbs up/thumbs down, for example) - it turns out the only way to get useful ratings is to make the choice very simple and then use the maths of it to work out what it really means on the basis of many people choosing.

And also to say, there is definitely a big psychological part in the easy/moderate/hard selection that varies depending on the player, before you even consider varying experience and expectations. (And of course relative difficulties depend on what you're comparing against too).

One thing would be to try pictures instead of words, e.g. stars or happy/unhappy faces - but it isn't obvious what the best choice would be. Stars really need a caption, so if you label 1 star easy and 3 stars hard that hasn't helped; and faces may not be so clear in meaning.

Any ideas, anyone? (If you do, please feel free to start a new topic in the 'Discussion forum' - only those who have this puzzle set can comment here).